Ignition-timing mechanism



' C. A. ROBERTSON IGNITION TIMING MECHANISM Filed Nov. 14. 1921 l M M m V m m MNM 'WN m W w l .l fLxHcl Patented June 1U, 19245.

CHARLES A. noiamaison,`

WARD a Co., inc., or CHICAGO, iLLinois, A CORPORATION or inninois.

IGNITION-miams MECHANISM.

Application filed November 14, 1921." Serial No.' 515,177.

To all whom t may concern: f

Be it known that I, CHARLES A. ROBERT- SON, a citizen of the United States, residing at Springfield, in the county of Sangamon and State of Tllinois, have invented certain new and useful improvements in Ignition- Timing Mechanism, of which the following is a specification. l

This invention relatestol control mechaiiism for internal combustion engines, and has to do particularly with an improved arrangement of means for timing and controlling the ignition incident to operation of the engine.

The general `purpose of the invention is the provision of an extremely simple'mechanism for timing the operation ofa magneto, or other energizing "source, relative to the operation of an internal combustion engine.

vAn incidental object is the provision of a simple construction for varying the timing ofthe ignition device within certain limits;

vAnother object-is the provisionv of a simple mechanism for operating a magnetoV in proper timing with Van internal combustion engine.

Other and further objects willrbe pointed out hereinafter, indicated in the appended' claims or made obvious-fromthe following description of a particular embodiment of the invention. This embodiment,A shown in the drawing forming a part of the specification, is here presented for the purpose of illustration merely, T being aware that the structure is susceptible of modificationl and variation without departing from the essential features which I regard as constituting my invention. I'

ln the drawing- Fig. 1 is a side View of-portions of an internal combustion engine, showing certain parts in sectional elevation; and

Fig. 2 is a detail showing the arrangement ofparts at the extremity of the igni mounted onfthe 'arm 16 by a trunnion 26.

tion arm.

Referring to these drawings in detail, let it be understood that the numeral 1 designates the cylinder of an internal com-- bustion engine in which the piston 2 operates. The engine shaft 4: carries anl-inertia wheel 5, and is driven by the piston through the instrumentality olf a connecting rod 6. A valve 7 controls exhaust from the cylinder 1. The engine shaft 4 carries a spur gear 8 Vwhich drives a timing; gear 9 which, inasniuch'as the present disclosure isintended t0 illustratev a four cycle engine, `'bears `a or SPRINGFIELD, intinoisiassienon 'ro MONTGOMERY, I'

gear ratioft'o the spur gearS, 'of two to one. i

lThe timing gear 9 'is lconjoined' to va -sleeve 10 which rotates on a post 11 as a bearing. The sleeve 10carries a timing cam-12 which is effective upon a roller 14. carried on a tappet rod 15 the rear end of which is bifurcated-for guidance upon the post 11. The forward extremity of the tappet rod 15 is connected vwith an ignition arm- 16 which is pivoted` at. 17 and restrainedl under the infuence4 of spring 18`to maintain the roller 14,' in operative-contact with the, cam 12;4 The ignition arm 16 constitutes a lever,the

upper arm', of which terminates in association with the trip lever 19 of an ignition device 20,l here illustrated as a magneto of the oscillating type. An -elect-rical conductor,

21 forms a path through whiclrenergyl may be transmitted toaproper ignition plug mounted in the engine cylinder. The magneto is of conventional form, and it will be' understood that'upon'therocking of the arm 19, which is pivoted ,at 19a, the conductor 21 will be energized to produce a spark at the terminals of the plug, this being ac complished at the quick return of the trip lever 19 to normal position under influence of the, springs 191.V swinging the trip lever 19 automatically and in proper time with the operation 'of the engine, T provide on the upper portion of the ignition arm 16 a pallet 2 2 which is pivoted at 22 in a slot in the upper end ofthe arm. This pallet at its rearward extremity has a nose portion 22b designed to contact a rollercarried on the trip ylever 19` of the magneto 20. Y Aspring 241 tends to rockthe pallet on its pivot and restrain its nose in raised position. The degreel of elevation of the `nose of the pallet is controlled byl an eccentric member 25 which' is rotatably A manually operable handle 27 extends As a means for thus' radially from the trunnion 26 and affords A means whereby the eccentric member 25 may be rotated.4 Incident lto operation Vof the engine, the shaft Llis rotated, driving timing gear 9 and reciprocating tappet rod.v 15

\ through the instrumentality of cam'12.V This Swings ignition arm 16 in proper time with the operation of the engine piston. As the upper end of the ignition arm swings rearwardly, the nose of the pallet 22 engages the roller at the lower extremity of the trip arm 19, swinging said arm rearwarly against the infiuence oi springs 191. When the lower end of trip arm 19 has thus been raised to a suitable elevation, the roller escapes over the nose of the pallet 22 and the lever is returned to normal position, in the course of said movement inducing energization of the conductor 21 and a resulting spark in the ignition plug. The extent to which the arm 19 is swung rearwardly, therefore, depends upon the elevati-on of the nose of the pallet 22. This, as stated above, is controlled by the adjustment of the eccentric member 25. To retard the spark therefore the eccentric member 25 is adjusted to raise the nose of the pallet, while to advance the spark the eccentric member 25 is adjusted to lower the nose of the pallet, thus permitting an earlier escape of the trip lever from it. Upon a forward movement of the upper end of the arm 16, the pallet escapes under the roller of the trip arm 19, the inclined top face of the pallet riding thereunder and inducing the rocking of the pallet against the influence of its spring 24. The device thus aords a simple mechanism for operation of the magneto by the engine, insuring operation thereof at the proper stroke of the piston, yet permitting a certain variation of the timing of the spark.

I claim:

1.Y in an internal gine including` an oscillating the combination of an oscillatory trip lever for actuating the magneto, au oscillatory ignition lever having a free end adjacent the free end ot the trip lever, means for oscillating the ignition lever to swing its free end across the free end of the trip lever, and a pallet carried by the free end of they ignition lever for engagement lwith the trip lever, said pallet being arranged to engage the trip lever on movement in one direction and 'to escape by the trip lever in movement in the opposite direction.

2. In an ignition timing mechanism of the class described, the combination with an internall combustion engine, and a magneto having an oscillatory trip arm, of an ignition lever having one of its ends mounted for oscillation with respect to the oscillatory trip arm of said magneto, means for operating said, ignition lever, a pallet pivotally mounted in said end orp said ignition lever, one of the ends of said pallet constituting a nose for engaging the trip arm of the magneto to actuate said arm in one direction, and means for adjusting the other end of said pallet to vary the contact relation of said nose with the trip arm of the combustion enmagneto,

intr/,oso

magneto, whereby to vary the period oi' engagement of the pallet and said trip arm.

3. In an ignition timing mechanism of the class described, the combination with an internal combustion engine, and a magneto having an oscillatory trip arm, of an ignition lever in substantial axial alignment with the trip arm of the magneto, means 'for oscillating said ignition lever with respect to said trip arm, a pallet arranged across the contiguous ends of said trip arm and ignition lever and having pivotal connection with the latter to be moved by the ignition lever transversely of the trip arm, one end of said pallet constituting a nose adapted to engage the trip arm to actu-ate the same in one direction, and means for adjusting the angular relation of the pallet to said ignition lever to vary the period of engagement of said pallet and trip arm.

4f. In an ignition timing mechanism of the class described, the combination with an internal combustion engine, and a magneto having an oscillatory trip arm, of an ignition lever having one of its ends mounted ior oscillation with respect te the oscillatory trip arm of said magneto, means for operating said ignition lever, a pallet pivotally connected across one end oiE said ignition lever, one of the ends of said pallet constituting a nose for engaging the trip arm of the magneto, means interposed between said end of the pallet and the. ignition lever for normally urging the engaging end away from the ignition lever, and an adjusting element cooperating with the other end ot the pallet to vary the contact relation oi the engaging nose with the trip arm of the magneto, whereby to vary the period of engagement of the pallet and said trip arm.

5. ln an ignition timing mechanism of the class described, the combination with an internal combustionr engine', and a magneto having an oscillatory trip arm, of an ignition lever having one of its ends mounted for oscillation with respect to the oscillatory trip arm of said magneto, means for operating said ignition lever, a pallet pivotally connected across one end oi' said ignition lever, one of the ends of said pallet constituting a nose for engaging the trip arm of the magneto, means interposed between said end of the pallet and the ignition lever for normally urging the engaging end away from the ignition lever, and an adjusting eccentric carried by the ignition lever and cooperating with the other end of the pallet to vary the contact relation of said nose with the trip arm of the magneto, whereby to vary the period of engagment of the pallet and said trip arm.

In testimony whereot` I have hereunto signed my name.

CHARLES A. ROBERTSON. 

